Such a vertical blind, in which the lateral displacement of the slats with their slat carriage in the support rail for opening and closing the blind, as well as the pivoting or tilting of the slats around their vertical central axis can be brought about by means of a single driving element, has been known from the German Offenlegungsschrift No. DE-OS 30,29,179. This driving element consists of a bead chain, which is led out of the support rail with a loop and is coupled in the support rail in the slat carriage leading in the closing direction of the slats with a tilting plate. The slat of this slat carriage is connected by spacing means arranged between the slats to all other slats, so that all slats can be pivoted around the vertical axis for a tilting process. Thus, lateral displacement of the slats in the closing direction and in the opening direction, as well as tilting of the slats is possible via the same pull cord, but tilting movements of the slats can be performed only at the end of a displacement movement when the blind is closed.
Grooved shafts for the tilting drive of the slats around their vertical axis and slip clutches between a gear through which the grooved shaft passes and a pinion on the tilting pin of the slat have been known from West German Offenlegungsschrift No. DE-OS 23,40,870 and West German Auslegeschrift No. DE-AS 25,54,351. According to these documents, slip clutches are provided in each of the slat carriages, so that increasing force has to be applied to operate the vertical blind by the pull cord as the number of slat carriages increases.